Amp repair advice

[reallybadusername36]

Hey guys, so this week my Randall RG75 started making a terrible feedback like noise that got louder and louder to the point I had to shut it off for a number of minutes. Nothing in my set up has changed, I was even using the same outlet that I usually do. After combing the threads for advice I have decided that since my amp is second hand and looks like its been ridden hard and put away wet so to speak it needs some good maintenance. I'm experienced enough in electronics that I feel comfortable in cleaning the connections and soldering parts that need touching up. However I'm looking for any other tips that you have to keep my amp in working condition or to avoid having a shocking experience. Thanks in advance.

 

[Flake]

Re: Amp repair advice

discharge the capacitors, properly check polarity for electrolytic ones, don’t mess with mosfets or any transistors unless you are absolutely sure that you know what you are doing


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[esandes]

Re: Amp repair advice

Discharging caps is not for beginners.

 

[Jacew]

Re: Amp repair advice

Discharging caps is not for beginners.

Well, it's not that hard. Just keep in mind there are LETHAL VOLTAGES there, and remember to DOUBLE CHECK everything with multimeter.

And use resistor when discharging.

Often they discharge on their own when you turn the amp off when playing, But NEVER TRUST THAT.

 

[evan47]

Re: Amp repair advice

If there is a tube in the pre amp that would be the most likely culprit. just try swapping it for a good one and see (or hear) if the problem is still there.

 

[67Mopar]

Re: Amp repair advice

Are you certain your pickup isn't causing the feedback?